Tim Wigmore works on the Morning Briefing email and was called a "little slave" by the Daily Politics Show. He blogs on British politics, and also contributes to ESPNcricinfo. He tweets @timwig.

Grammar schools and the myth of social mobility

There is a forgotten schools revolution. And it's not the opening of new free schools, the rise of academy status or Michael Gove's sweeping changes to the curriculum. It's the quiet rise of grammar schools.

Five percent of secondary school pupils are now educated at grammar schools. That may not sound like a lot, but the number has surreptitiously grown over the past 25 years; in 1986, it was only three percent. Although the number of grammars has now stabilised at 164, their pupil numbers continue to rise. And a good thing, too: grammar schools smash open the citadels of the Establishment to anyone with enough talent and hard-work.

Except, they don't. But no educational myth has proved as enduring as that of the grammar school.

We don't have to imagine a parallel universe in which the grammar school didn't die. We can look at Kent, which still has 33 grammar schools left today. The poorest children in the county fare worse than the national average. Overall school performance in Kent mirrors that in England as a whole – but only because the inferior results of the poorest children is made up for by those with the wealthiest parents doing better. Grammar schools in Kent choke social mobility rather than enable it.

But the appeal of grammar schools has always been rooted in nostalgia rather than facts. A grammar school in every town; opportunity for all, regardless of background. It's a seductive idea – but also a simplistic and populist one. Drawing a line between pupils based on the 11-plus was crude and, for those on the wrong side of it, devastating to their future life chances.

Who really benefited from grammar schools? A 1954 government study showed that, of 16,000 grammar school pupils from semi-skilled or unskilled backgrounds, around 9,000 failed to get three passes at O-Levels, with 5,000 leaving school at 16. A Sutton Trust study in 2008 found that fewer than two per cent of those attending grammar school received free school meals, compared to 5.5 per cent at non-selective schools. And, like all exams, the 11-plus provides recession-proof business for private tutors, which helps explain why grammar school pupils in Kent today are nearly twice as likely to have previously been privately educated as in the county at large.

Famously, three PMs out of four – Wilson, Heath and Thatcher – attended grammar schools. None were from wealthy families, but neither were they the working-class children made good that they presented themselves as. Rather, they were fundamentally middle-class products of a middle-class system. The success of the grammar school brigade was driven by the sheer numbers who attended them: 25 per cent of children went to grammar schools in 1963. And, as a British Journal of Sociology study in 2011 put it, "any assistance to low-origin children provided by grammar schools is cancelled out by the hindrance suffered by those who attended secondary moderns".

Improving social mobility is a laudable aim, but thinking that can be achieved through building a grammar school in every town is nothing more than fool's gold. The social mobility supposedly unleashed by the grammar school system was a myth.